binCI {FSA}R Documentation

Confidence intervals for binomial probability of success.

Description

Uses one of three methods to compute a confidence interval for the probability of success (p) in a binomial distribution.

Usage

binCI(
  x,
  n,
  conf.level = 0.95,
  type = c("wilson", "exact", "asymptotic"),
  verbose = FALSE
)

Arguments

x

A single or vector of numbers that contains the number of observed successes.

n

A single or vector of numbers that contains the sample size.

conf.level

A single number that indicates the level of confidence (default is 0.95).

type

A string that identifies the type of method to use for the calculations. See details.

verbose

A logical that indicates whether x, n, and x/n should be included in the returned matrix (=TRUE) or not (=FALSE; DEFAULT).

Details

This function will compute confidence interval for three possible methods chosen with the type argument.

type="wilson" Wilson's (Journal of the American Statistical Association, 1927) confidence interval for a proportion. This is the score CI, based on inverting the asymptotic normal test using the null standard error.
type="exact" Computes the Clopper/Pearson exact CI for a binomial success probability.
type="asymptotic" This uses the normal distribution approximation.

Note that Agresti and Coull (2000) suggest that the Wilson interval is the preferred method and is, thus, the default type.

Value

A #x2 matrix that contains the lower and upper confidence interval bounds as columns and, if verbose=TRUE x, n, and x/n .

Note

This is primarily a wrapper function for binom.exact, binom.wilson, and binom.approx (documented in binom.conf.int) from the epitools package.

Author(s)

Derek H. Ogle, derek@derekogle.com

References

Agresti, A. and B.A. Coull. 1998. Approximate is better than “exact” for interval estimation of binomial proportions. American Statistician, 52:119-126.

See Also

See binom.test; binconf in Hmisc; binom.exact, binom.wilson, and binom.approx documented in binom.conf.int in epitools, and functions in binom.

Examples

## All types at once
binCI(7,20)

## Individual types
binCI(7,20,type="wilson")
binCI(7,20,type="exact")
binCI(7,20,type="asymptotic")
binCI(7,20,type="asymptotic",verbose=TRUE)

## Multiple types
binCI(7,20,type=c("exact","asymptotic"))
binCI(7,20,type=c("exact","asymptotic"),verbose=TRUE)

## Use with multiple inputs
binCI(c(7,10),c(20,30),type="wilson")
binCI(c(7,10),c(20,30),type="wilson",verbose=TRUE)


[Package FSA version 0.8.26.9000 Index]